Geoffrey II of Brittany

Geoffrey II of Brittany (23 September 1158-19 August 1186) was Duke of Brittany from July 1181 to 19 August 1186, interrupting Constance of Brittany's two reigns.

Biography
Geoffrey was born on 23 September 1158, the son of Henry II of England and Eleanor of Aquitaine. In July 1181, he married the heiress to the Duchy of Brittany, Constance of Brittany, as a part of a diplomatic agreement with Conan IV of Brittany (despite her being only five and Geoffrey 23). Geoffrey therefore inherited Brittany. In 1183, he joined a revolt against his father alongside his brother Henry the Young King, but the rebellion failed; Geoffrey was constantly allied to Philip Augustus of France against his father. Geoffrey gained a poor reputation among the clergy due to his sacking of churches to raise funds for his mercenary army, and he was called a "deceiver and disassembler" by Gerald of Wales. He died in 1186, and Constance became duchess of Brittany once more.